As investigators begin to examine the devastating collapse of a school in Italy in Thursday's earthquake, questions are being asked about the construction of the building.

An expert in disaster management has said the construction was likely to have been a "botched job".

David Alexander, a professor at the Cranfield Disaster Management Centre in the UK who has nearly 30 years experience in Italy, said he believed the school had "been built on the cheap", although not necessarily illegally.

I can say for definite from the pictures that it was built with poor quality concrete

David Alexander, disaster management expert

Investigators in the southern city of San Giuliano di Puglia will try to determine what happened and who, if anyone, is to blame.

The Italian senator Tana de Zulueta said people living in the community wanted answers as to why it collapsed and why pupils and teachers were not evacuated.

Mr Alexander told BBC News Online that the school could have been badly retro-fitted.

"I can say for definite from the pictures that it was built with poor quality concrete. The reinforcing looks poor, too. Generally a reinforced concrete building can withstand a quake on the scale of 5.4."

Poor maintenance

He said that it was not unusual in small, rural communities that the schools were poorly maintained.

"Areas like San Giuliano are not economically buoyant and are becoming relatively depopulated. There isn't enough money to look after the old buildings properly," he said.

Other buildings in the town were hit but not as badly as the school

According to reports, the school was built in the late 1950s and had been substantially modified. Investigators will examine these changes closely.

In 1997, Italy suffered from what Mr Alexander calls an "earthquake swarm", which saw about three months of significant seismic activity.

Many of the buildings collapsed, he said, because they were of mixed construction, meaning that they had been added to over the years.

"Different construction types react in different ways to seismic shaking. The lesson learnt then was that mixed construction can be a death-trap unless it is done in a way to withstand earthquakes," Mr Alexander said.

Seismically active

It is not clear whether the school had been seismically reinforced. Reports suggest that at the time it was built, the municipality was not registered as seismically active, although that classification was changed at a later date.

Some buildings are made anti-seismic later, but it is crucial the structure is sufficiently integrated, Mr Alexander said.

There are several thousand seismically active communities across Italy. But experts say many are unprepared for disasters, such as quakes and floods.

Earlier in the week, Sicily was rocked by an earthquake

Investigators in San Giuliano are likely to look at how the evacuation of the area was handled by the authorities.

According to Mr Alexander, the area was not very well versed in disaster management.

"The region has started to put together a modern civil protection system, which would have included earthquakes, but it was a bit late in the day," he said.

Building-related disasters

He added that some of the bigger cities have some of the best advance emergency planning systems in Europe, but that the rural areas had been neglected.

Italy has suffered a number of building-related disasters, not all caused earthquakes.

When an apartment block near Rome crumbled in 1999, killing more than 30 people, it emerged that a post-war development frenzy had created more than three million buildings at risk of collapsing.

A survey by an independent research agency suggested that many of those buildings were at risk due to age, others due to technical weakness and many had been built illegally.

The government announced plans to enforce a survey of older buildings, listing their date, modifications and condition.

Experts say that a number of cities - Naples in particular - have successfully listed old buildings but many rural areas have lacked the funding and expertise to carry out such a programme.